( 358 ) 



2. Two side line*, each at a distance of ^ n^'—^i trom the 

 preceding one. Their intensities are 



J<Ii^%" L9] and ~q,^qr~ [9] . 



B. The following lines will be produced by vibrations perpen- 

 dicular to the lines of force. 



1. Two lines at distances )i.2 — n-^' from A,l. Intensities: 



^qi'qi'" [9] and ^^ rj,^ g,'^ U^] . 



2. Two lines at distances | «'o from A^l. Intensities: 



9 . o r9l 9 , , „ [9] 



-y3^y3-[yJaBd-y3^.yr [-\. 



3. Two lines at distances n'l from -^,1. Intensities: 



-yi^y,"[-Jand-9,~,,-|_-J. 



In the observations along the lines of force, the lines B only 

 will be seen, with the same relative intensities. 'J'hey will then be 

 circularly polarized. 



Of course, the source of light will contain innumerable molecules 

 for which the quantities q and q' will have widely different values. 

 Assuming that both the vibrations of the first and those of the 

 second order take place indifferently in all directions, and that even 

 a particular vibration of one kind may be equally accompanied by 

 vibrations of the other kind in all possible directions, I find for 

 the relative intensities the numbers inclosed in brackets. 



Perhaps the way in which the ions are made to vibrate will be 

 unfavourable to the existence at the same time of certain particular 

 vibrations of the first and the second order; some of the derived vibra- 

 tions would then have a smaller intensity than the one indicated. 

 As to the middle line .^,1, it must always be weakened by ab- 

 sorption in the exterior parts of the source. Yet, in the case of 

 luminous particles of a symmetrical structure, it seems impossible 

 that this central line should ever vanish altogether. 



§ 15. If there were no ZEEMAN-efi'ect for the vibrations of the 

 first order, we should have n\ = 0, and the lines B, 3 would form 



